Alternative formats

Down syndrome in Israel

Joav Merrick

The incidence of Down syndrome was studied in Jerusalem for the years 1964-1970 showing an overall incidence rate of 2.43 per 1,000 live births. A National Down Syndrome Register was established in 1978 and data on annual incidence and mortality rates from 1979-1997 is presented. The incidence in 1997 was 1.0 per 1,000 live births, but 2.32 per 1,000, when live births and terminated pregnancies are summed. Infant mortality has generally decreased in the past 20 years in Israel, and a decrease in infant mortality in Down syndrome has also been noted. This is due to better medical treatment and increased parental involvement in the care for infants with Down syndrome.

Merrick, J. (2001) Down syndrome in Israel. Down Syndrome Research and Practice, 6(3), 128-130. doi:10.3104/reports.104

Introduction

There has been a decline in infant mortality in Israel over the last 25 years. In
1997 the infant mortality rate for Jews was 4.9 per 1,000 live births, whereas for
Arabs it was 9.3 resulting in a total rate of 6.2 (Ifrah,
1999).

This decline affects Jews as well as Arabs, with an especially marked decline in
mortality due to infectious causes.

Congenital malformation continues to be the commonest cause of infant mortality
although there has been a 61% decrease among Jews (and 38% decrease among Arabs)
in mortality from this cause since 1970. Contributing causes for the difference
between Jews and Arabs could be due to the higher extent of consanguineous marriage
in the Arab population and a lower utilisation of prenatal screening.

Prenatal screening

Screening tests for carriers of the Tay-Sachs gene started in 1974, and in 1978
a national program for the prevention of births defects was implemented by the Ministry
of Health. Since 1979 data has been collected and analyzed on the births of infants
with Down syndrome. The Down Syndrome National Register receives information from
routine notifications from delivery rooms, cytogenetic laboratories in all hospitals
and annual reports from hospital nurseries.

In 1978 free amniocentesis was offered to women over the age of 37 years, but since
1993 the age limit has been reduced to 35 years. The use of amniocentesis was 61%
in pregnant Jewish women (over 35 years) in 1997 and 14% in younger women with a
total 22.2% of all pregnant Jewish women. For Arab women the total utilisation was
4.2% (Ifrah, 1999). The use of amniocentesis
in the target group of women over 35 years is higher than in other countries (England,
the United States, Holland, Australia), where Steele and Stratford (1995)
found no more than 50% utilization.

In 1990, 53% of the cases of Down syndrome among Jewish women were detected and
terminated during pregnancy, whereas in 1997 this percentage had increased to 61.2%.
In the Arab population 8% of pregnancies with Down syndrome were terminated in 1991,
whereas in 1997 that figure had increased to 35.7% (Ifrah,
1999).

In 1997, there were 86,140 births among Jewish women and 38,338 amongst Arab women
with the number of amniocenteses performed being 19,135 and 1,607 for Jewish and
Arab women respectively. The total number of cases of Down syndrome diagnosed antenatally
was 219 cases among Jewish women and 70 among Arab women. There were 85 live births
among Jewish women and 45 live births among Arab women and 134 terminations among
Jewish women and 25 terminations among Arab women during this period (Ifrah,
1999).

Trends in the incidence of Down syndrome

A prospective study from Jerusalem (Harlap, 1973)
followed about 42,000 deliveries and found 103 infants with Down syndrome between
the years 1964-1970. The incidence rates according to maternal age can be seen in
Table1. The overall incidence rate for the period was 2.43
per 1,000 births with a tendency to increasing incidence with increase in maternal
age. This rate is higher than some other countries during the same period, e.g.
Australia (1.19), England (1.39) and the United States (1.44) (Steele,
1996).

The Ministry of Health in Israel started a National Program for Detection and Prevention
of Birth Defects in 1974 and has collected data on Down syndrome since 1979. The
number of live births and the incidence rate for Jews and non-Jews is shown in Table 2 (Klein
et al., 1998). The total or true incidence rate for Down syndrome
in 1997, including both live births and terminated pregnancies, for Jews and non-Jews
was 2.32 per 1,000. This rate is not appreciably different from the rate found for
the years 1964-1970 (Harlap, 1973), namely 2.43.

Table 2. Total number of live birth persons with Down syndrome
and incidence rates for Jews and non-Jews in Israel 1979-1997.

Year

Total number of live births with Down syndrome

Rate per 1,000 live births for Jews

Rate per1,000 live births for non-Jews

1979

109

1.1

1.5

1980

107

1.0

1.4

1981

111

1.1

1.5

1982

128

1.3

1.5

1983

125

1.3

1.2

1984

120

1.2

1.3

1985

131

1.3

1.4

1986

131

1.3

1.3

1987

130

1.5

0.9

1988

123

1.3

0.9

1989

116

1.1

1.2

1990

103

1.0

1.1

1991

97

1.0

0.8

1992

115

0.7

1.8

1993

114

0.9

1.3

1994

96

0.7

1.2

1995

107

0.8

1.2

1996

105

0.9

0.9

1997

130

1.0

1.2

Trends in mortality

About 85% of deaths due to congenital malformations occur during the first year
and a further 10% during the second to fourth years of the child's life. In 1995
the mortality rates in the 0-4 age group were 39.7 per 100,000 for Jewish males,
27.4 for Jewish females and, 89.2 for males and 80.9 for females in the Arab population.
Mortality due to congenital malformations declined in the years 1970-1995 by 70%
for Jewish males, 76% for Jewish females and 47 % for Arab males and 46 % for Arab
females (Ifrah, 1999).

Infant mortality (deaths until the end of the first year) for children with Down
syndrome is shown in Table 3 and mortality up to the age of
14 years is shown in Table 4 (Klein
et al., 1998).

Table 3. Infant mortality (until year one) for children
with Down syndrome in Israel 1979-1996.

Year

Number of deaths

Percentage of total

1979

50

45.9

1980

52

48.6

1981

35

31.5

1982

41

32.0

1983

34

27.2

1984

33

27.5

1985

23

17.6

1986

25

19.1

1987

22

16.9

1988

23

18.7

1989

24

20.7

1990

14

13.6

1991

13

13.4

1992

22

19.1

1993

22

19.3

1994

10

10.4

1995

11

10.3

1996

9

8.6

These figures demonstrate a clear decrease in mortality since 1979. This decrease
is caused by several factors. Firstly, because of technical developments in medicine,
such as improved surgical techniques for cardiac and gastrointestinal malformations.
Secondly, earlier and more effective medical treatment of infections and thirdly,
a change in attitude both by parents, and also by medical and nursing staff in hospitals
towards a much more positive attitude towards children born with Down syndrome (Sadetzki
et al., 1999a,
Sadetzki et al., 1999b).

Table 4. Mortality of children with Down syndrome until
age 14 in Israel 1979-1996.

Year

Number of deaths

Percentage of total

1979

63

57.8

1980

64

59.8

1981

44

39.6

1982

54

42.2

1983

43

34.4

1984

41

34.2

1985

39

29.8

1986

40

30.5

1987

33

25.4

1988

35

28.5

1989

36

31.0

1990

27

26.2

1991

21

21.6

1992

32

27.8

1993

28

24.6

1994

14

14.6

1995

13

12.1

1996

11

10.5

Conclusion

The total incidence of Down syndrome during the years 1964 through 1970 was found
to be 2.43 per 1,000 live births. Data from the National Down Syndrome Register
for the years 1979 through 1997 showed a decline in the incidence, but when live
births and terminated pregnancies were summed the true incidence rate in 1997 was
2.32. Mortality rates have shown a clear decline since 1979 due to medical advances,
but also due to a much more positive public attitude towards persons with Down syndrome
in Israeli society.

Online stores

Down Syndrome Education Organisations

DSE works to improve education and early intervention for children with Down syndrome.
Our research and evidence-based services and resources are helping thousands of young people with Down syndrome to achieve more than ever before.

With your support, we can accelerate research, develop new services and resources, and provide support and advice to more families and professionals everywhere.